Stand mixers

ABSTRACT

A stand mixer 10 comprises a head unit 50 having a lower surface presenting, in operation, a downwardly-facing drive outlet for driving in rotation at least one tool suspended therefrom. The head unit is supported with the downwardly-facing drive outlet above a receiving location 30 for a mixing bowl 40. Driving means, including an electric motor 70 and associated transmission means for conveying rotary drive to the drive outlet, are provided. The mixer further comprises first 80 and second 90 coaxial driving outlets presented on an upper surface 52 of the head unit 50; the coaxial outlets 80, 90 run at different speeds and are driven from the motor 70 by means of an epicyclic gearbox 100. The motor 70 is housed in the support means 60 with its drive shaft 72 in substantial alignment with the coaxial drive outlets 80, 90.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. application Ser.No. 15/029,425 filed Apr. 14, 2016, which is a 371 U.S. National Stageof International Application No. PCT/GB2014/053593, filed on Dec. 3,2014 and claims priority to Great Britain Application No. 1321291.5,filed Dec. 3, 2013. The entire disclosures of the above applications areincorporated herein by reference.

BACKGROUND

This invention relates to stand mixers, by which is meant the kind ofmotor-driven kitchen machine which is used to mix, or otherwise process,ingredients in a bowl by powered movement of one or more shanked toolswhich depend into the bowl from a head unit that carries adownwardly-facing drive outlet, powered by the motor, to which theshank, or shanks, of the tool, or tools can be fitted for use.

Such mixers conventionally comprise a generally C-shaped casing whichprovides a pedestal-like support for a mixing bowl, and a generallyupright support portion supports the head unit so that it extendsoverhead of the bowl. Moreover, the powered movement of the shanked toolor tools is often, though not necessarily, planetary in nature.

Stand mixers such as the Kenwood Chef kitchen machine are well known andhave been well established in use for many years. Over the years, mixersof this kind have been adapted and developed so as to perform an everbroadening range of functions, and many such appliances provide, forexample, a plurality of additional drive outlets running at differentspeeds and with differing torque characteristics, thus enabling them todrive a number of attachments, such as blenders and mincers, which,between them, can perform a wide range of tasks. This is beneficial forthe user, because a single machine can be used to selectively hostseveral attachments and thus perform a range of tasks which wouldotherwise require the purchase and storage of several bespoke kitchenmachines, each with their own motors and associated equipment.

Typically, the additional drive outlets are located at different placeson the stand mixer body, depending to an extent on the configuration andpurpose of the attachments they are to drive. In particular, it is usualfor a high-speed outlet, capable of powering a blender attachment, forexample, to be provided on the upper surface of the head unit and closeto its junction with the upright portion of the stand mixer's casing.

If the stand mixer is also intended to drive a food processorattachment, however, it is necessary either to provide a separate outletelsewhere on the stand mixer or to provide a separate, external gearboxthat can be coupled to the blender drive outlet to reduce the drivingspeed and also convert the drive outlet configuration to one that cancouple to a conventional food processor bowl. Neither option isparticularly desirable, since the provision of separate drive outletsfor blender and food processor attachments is awkward and costly,requiring additional gears and pick-offs from the main drive train, andthe storage and fitment of separate gearboxes is a nuisance for theconsumer.

It is also necessary to provide an economical and robust couplingbetween the motor and its primary drive train, the additional outletsand the slow-speed planetary or other drive outlet used to power theaforementioned shanked tool or tools, such as dough hooks and the like,which are provided for mixing ingredients placed in the bowl that standson the pedestal beneath the head unit.

It is an object of the invention to address some at least of the aboveconsiderations and, in accordance with one aspect of the invention thereis provided a stand mixer comprising a head unit having a lower surfacepresenting, in operation, a downwardly-facing drive outlet for drivingin rotation at least one tool suspended therefrom, support means forsupporting said head unit with said downwardly-facing drive outlet abovea receiving location for a mixing bowl, and driving means including anelectric motor and associated transmission means for conveying rotarydrive to said drive outlet, the mixer being characterised by theprovision of first and second coaxial driving outlets presented on anupper surface of said head unit; said coaxial outlets running atdifferent speeds and being driven from said motor by means of anepicyclic gearbox; the motor being housed in said support means with itsdrive shaft in substantial alignment with said coaxial drive outlets. Bythis means, attachments requiring different driving characteristics canbe driven from the inner or outer of the coaxial outlets as appropriatein a stable and convenient manner.

The provision of (preferably, at least) two coaxial drive outletsoperable at distinct speeds improves the range of attachments (forexample, to include high and low speed attachments) that may be drivenby the stand mixer. Furthermore, the downwardly-facing drive outlet thatis, preferably, offset from the coaxial drive outlets may be usedsimultaneously alongside one (or both) of the coaxial drive outlets.Advantageously, the downwardly-facing drive outlet and coaxial driveoutlets are driven by the same motor and epicyclic gearbox arrangement,thereby eliminating the need for each drive outlet to have a separatemotor and corresponding gearing.

Preferably, the inner of said coaxial drive outlets and the sun wheel ofsaid epicyclic gearbox are driven directly, and at a relatively highspeed (i.e. the operating speed of the motor), by said drive shaft, andthe outer of said coaxial drive outlets is driven, at a lower speed thenthe inner drive outlet, from a planet carrier of said gearbox.

In a preferred arrangement of the above kind, said transmission meansincludes transfer means configured to convey, from said epicyclicgearbox to said downwardly-facing drive outlet, rotational drive at asubstantially lower speed than said outer drive outlet. Advantageously,the downwardly-facing drive outlet is operable by means of the motor andthe epicyclic gearbox.

It is particularly preferred that said transfer means comprises a beltand pulley system, and that the driven pulley of said belt and pulleysystem is driven from the planet carrier of said epicyclic gearbox.

Conveniently, in such a system, the driven pulley and a driving memberfor the outer of said coaxial outlets are integrally formed and aresecurely but removably attached to said planet carrier.

Preferably, in such circumstances, said planet carrier is of metallicconstruction and formed with a central aperture to accommodate the driveshaft of said motor; a lip region of the planet carrier surrounding theaperture supporting an axially-extending central plastic drive form,overmoulded thereon, which presents external surface featurescomplementary to internal surface features formed centrally of the saidintegral driving member and driven pulley, whereby the said integraldriving member and driven pulley can be press-fitted to said drive form.

Further preferably, the external surface of the drive form is providedwith one component of an annular clip, the other component of which isprovided on the internal surface of said integral driving member anddriven pulley whereby, when press-fitted together, the two components ofthe clip snap into place, thereby latching the driving member and drivenpulley securely to the drive form, but facilitating their separation, byunclipping them, if required for servicing.

SUMMARY

In preferred embodiments, the mixer further comprises means associatedwith said coaxial outlets for encouraging fluid spilt in the vicinity ofsaid coaxial outlets to flow into a collection means, and further meansadapted to conduct collected fluid out of the mixer; thereby impedingingress of said fluid into said gearbox.

For safety, preferably, the stand mixer is enveloped by a casing, withinwhich the first and second coaxial driving outlets are recessed.

According to another aspect of the invention, there is provided a kitcomprising: a stand mixer, preferably as described above; a firstattachment for coupling to a first drive outlet of the stand mixer; asecond attachment for coupling to a second drive outlet of the standmixer; and a tool for coupling to a downwardly-facing drive outlet ofthe stand mixer.

The invention extends to a stand mixer substantially as described withreference to and/or as shown in the accompanying drawings. The inventionalso extends to a kit substantially as described with reference toand/or as shown in FIGS. 2 and 3.

The invention extends to methods and/or apparatus substantially asherein described with reference to the accompanying drawings.

The invention also provides a computer program and a computer programproduct for carrying out any of the methods described herein and/or forembodying any of the apparatus features described herein, and a computerreadable medium having stored thereon a program for carrying out any ofthe methods described herein and/or for embodying any of the apparatusfeatures described herein.

Any apparatus feature as described herein may also be provided as amethod feature, and vice versa. As used herein, means plus functionfeatures may be expressed alternatively in terms of their correspondingstructure, such as a suitably programmed processor and associatedmemory.

Any feature in one aspect of the invention may be applied to otheraspects of the invention, in any appropriate combination. In particular,method aspects may be applied to apparatus aspects, and vice versa.Furthermore, any, some and/or all features in one aspect can be appliedto any, some and/or all features in any other aspect, in any appropriatecombination.

It should also be appreciated that particular combinations of thevarious features described and defined in any aspects of the inventioncan be implemented and/or supplied and/or used independently.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be clearly understood and readilycarried into effect, some embodiments thereof will now be described, byway of example only, with reference to the accompanying drawings, ofwhich:

FIG. 1 shows, in cross-sectional view, a stand mixer in accordance withone embodiment;

FIG. 2 shows a blender attachment coupled to the mixer of FIG. 1;

FIG. 3 shows a food processor attachment coupled to the mixer of FIG. 1;

FIG. 4 shows, in perspective and exploded view, certain criticalcomponents of the mixer shown in FIG. 1; and

FIG. 5 shows the components of FIG. 4 in exploded and cross-sectionalview.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring now to FIG. 1 of the drawings, a stand mixer 10 in accordancewith a first embodiment comprises a base part 20, which includes apedestal 30 for locating and supporting in an operational position aprocessing bowl 40 to contain ingredients for processing. The standmixer 10 also includes a head part 50 which is supported and linked tothe base part 20 by a generally upright portion 60.

The upright portion 60 comprises two parts; a lower part 60 a which isintegrally formed with the base 20, and an upper part 60 b which isintegrally formed with the head part 50 and is hingedly mounted to thelower part as shown so that, in conventional fashion, the head part canbe raised relative to the base to facilitate the insertion and removalof the bowl 40 and/or of shanked mixing tools. The upper part 60 b ofthe upright portion 60 houses an electric drive motor 70 driving a maindrive shaft 72 that, in conventional manner, is journalled in upper andlower bearings 74 and 76 to rotate smoothly around its longitudinal axis78 which of course is also the axis of the motor 70. It will beappreciated by those skilled in the art that any type of electric motorcapable of appropriately powering the drive outlets of the stand mixer10 can be used, and the particular form of motor shown in FIG. 1 isshown by way of example only.

In this embodiment, the shaft 72 is used to directly drive a high speeddrive outlet spigot 80 that can be used to power the blades 84 of ablender attachment, for example, at the operating speed of the motor 70.This is a beneficial and economical arrangement, since no intermediategearing is required. FIG. 2 shows a blender attachment 82 coupled to theoutlet spigot 80.

As can be seen from the drawing, the location of the outlet spigot 80 issited on, or preferably recessed within, the upper surface 52 of thehead unit 50 and directly above the motor 70, on the axis 78 of the maindrive shaft 72. This is a convenient location for usage of theattachment 82, and it provides a stable configuration, since all of therelevant components are axially aligned.

In a particularly beneficial arrangement, the invention further providesa second, lower speed, drive outlet ring 90 which coaxially surroundsthe outlet spigot 80. This permits attachments such as food processorsand juicers, which need to be run at slower speeds than the blender 82,to be attached to the stand mixer 10 at the same stable location as thehigh-speed drive outlet 80. FIG. 3 shows a food processor attachment 92coupled to the outlet ring 90. The attachment 92 in this case is fittedwith a tool in the form of a disc-type cutter 94. However, as is wellknown, food processor attachments such as 92 can accommodate variousdifferent tools, such as blades, and the discoidal tool 94 is shown byway of example only.

It will be appreciated that the attachments 82 and 92, when coupled tothe drive outlets 80 and 90 respectively for use, utilise known forms of“through-the-base” drive couplings to transfer the rotational drive fromthe outlets 80 and 90 to rotatable food-processing tools such as 84 and94 respectively, mounted within blending goblets, such as 86, orfood-processing bowls, such as 96, of the attachments 82 and 92 asappropriate. Such goblets and bowls are preferably fitted with closeablelids, and moreover safety interlocks of known kind are preferablyprovided to prevent the tools being driven unless the appliance is setup for safe operation.

The arrangement of drive outlets 80, 90 allows for a greater dynamic ofoperability of the stand mixer than if only one such outlet wereprovided. In one example, given that the output speeds imparted to anattachment is dependent upon—in part—the outlet to which a tool iscoupled, both high and low speed attachments are available to beoperated via outlets 80 and 90 respectively.

In one example, the blades 84 of a blender attachment (or anotherappropriate high-speed attachment) are driven by the high speed driveoutlet spigot 80. The discoidal cutter of a food processor (or anotherappropriate low-speed attachment) is driven by the lower speed outletspigot 90.

When the stand mixer is in use, the low speed and high speed outletspigots operate simultaneously, along with the downwardly-facing driveoutlet.

In a particularly preferred arrangement, as shown in FIG. 1, the coaxialoutlets 80 and 90 are provided by way of an epicyclic gearbox 100configured such that its sun wheel 102 is directly driven by the mainshaft 72. In this embodiment, there are three planet wheels such as 104,all driven by the sun wheel 102 and running within a fixed ring gear 106which of course is centred on the axis 78 of the shaft 72.

The planet wheels such as 104 are all associated with a planet carrier108 which rotates coaxially with, but at a slower rate than, the shaft72. The carrier 108 is mounted to drive the ring outlet 90 and, by thismeans, an efficient and convenient coaxial dual-drive arrangement isprovided capable of driving attachments with differing speed and torquerequirements. The coaxial drive outlets are, moreover, sited at aconvenient and stable location on the mixer 10. Furthermore, andimportantly, the epicyclic gearbox 100 has a shallow envelope, measuredalong the axis 78, which permits the working height of the mixer's headunit 50 to be minimised; thus creating a relatively low operationalcentre of gravity for the attachments to the coaxial drive outlets andfurther enhancing the stability of the appliance as a whole. All ofthese features are clearly evident from the accompanying drawings; inparticular FIGS. 2 and 3.

In a particularly beneficial configuration, the planet carrier 108,which provides the lower speed drive for outlet ring 90, is alsoarranged to turn a drive pulley 110 which carries a drive/timing belt115 that is also connected to another pulley 120 and used to power themain slow-speed mixer/mincer outlet 130 of the mixer 10. In thisexample, the slow-speed outlet 130 is driven by way of another epicyclicgearbox 132 utilising bevelled planet gears, but it will be appreciatedthat any convenient planetary or fixed-axis drive can be employed. Ofimportance in this embodiment is the fact that the main drive from theshaft 72 is not only directly available for the coaxial drive outlets 80and 90 but is also conveyed efficiently and economically to theslow-speed drive outlet 130 which, in most cases, is the principaloutlet of the mixer 10 and is used principally for mixing, kneading andother food processing operations in the bowl 40.

FIGS. 4 and 5, to which reference will now additionally be made, showthe detailed construction of the epicyclic gearbox, its relationship tothe coaxial drive outlets 80 and 90, and its association with otherrelevant components.

The working components of the gearbox 100 are housed within a casingcomprising, on the one hand, the ring gear 106 with an associated base140 that is centrally apertured to accommodate the shaft 72, and, on theother hand, a top cover plate 142 that is also apertured to permit theshaft 72 to pass therethrough. The casing components 106, 140 on the onehand and 142 on the other hand are, in this example, formed with thenecessary fitments to enable them to be assembled together by means ofthe so-called “poke-yoke” system. Upper and lower gearbox bearings 144and 146, located in the central apertures of the top cover plate 142 andthe base 140 respectively, are provided for the shaft 72 to help absorbthe transverse loadings imparted to the system by the drive/timing belt115 via the pulley 110. The sleeve 144 a for the upper bearing 144 isalso shown.

In this preferred embodiment, the planet carrier 108 is formed of sheetmetal, and is overmoulded with a plastics drive form 148 which providesnot only external surface features 150 complementary to internal surfacefeatures 152 formed in the drive ring 90 and utilised to couple themotion of the planet carrier 108 to the drive outlet ring 90, but also aspillage retaining wall 154, the provision of which is one of a numberof steps taken to reduce the risk of liquid spillage from theattachments 82 or 92 entering the gearbox 100, as will be explained inmore detail hereinafter.

The drive outlet ring 90 is integrally formed with a lower extensionproviding the pulley 110 so that, when assembled, both components aredirectly driven by the drive form 148 overmoulded to the planet carrier108. By this means an efficient and economical drive system is provided.The ring 90 is pushed on to the drive form 148 so that the externalsurface features 152 of the drive form 148 mesh tightly with theinternal surface features 152 of the ring 90, and the two components arefastened together by means including a retaining clip 156 integratedinto the drive form 148. The parts 90 and 148 can be separated ifrequired for servicing by manipulation of the retaining clip 156.

The central, high-speed drive outlet spigot 80 is fitted to the end ofthe shaft 72 and firmly secured thereon by any convenient means fornon-slipping rotation with the shaft 72.

It has previously been mentioned that steps, including the provision ofthe spillage retaining wall, are taken to reduce the risk of fluidsspilt in the vicinity of the drive couplings 80, 90 from entering thegearbox 100. Additional features used in this respect include a drainageaperture 158 formed in the ring 90 above the rim of pulley 110. Thisaperture 158 co-operates with the retaining wall 154 to encouragespillage to exit the system, away from the shaft 72. Spilt fluidsexiting the aperture 158 are collected by a plastics collection member(or so-called drip tray) 160, which is fixed in place, and is configuredto collect spillage and channel it safely to the exterior of theappliance by way of a series of channels and drainage holes.

It will be understood that the present invention has been describedabove purely by way of example, and modifications of detail can be madewithin the scope of the invention.

Each feature disclosed in the description, and (where appropriate) theclaims and drawings may be provided independently or in any appropriatecombination.

Reference numerals appearing in the claims are by way of illustrationonly and shall have no limiting effect on the scope of the claims.

What is claimed is:
 1. A stand mixer comprising: a head unit having alower surface presenting, in operation, a downwardly- facing driveoutlet for driving in rotation at least one tool suspended therefrom;support means for supporting said head unit with said downwardly-facingdrive outlet above a receiving location for a mixing bowl; driving meansincluding an electric motor having a drive shaft, and associatedtransmission means for conveying rotary drive to said downwardly-facingdrive outlet, the motor being housed in said support means; first andsecond coaxial driving outlets presented on an upper surface of saidhead unit, said first and second coaxial outlets running at differentspeeds; and an epicyclic gearbox arranged to be driven by the motor, andarranged to drive the first and second coaxial drive outlets; whereinthe first coaxial drive outlet and a sun wheel of said epicyclic gearboxare driven at a relatively high speed by said motor, and wherein thesecond coaxial drive outlet is driven at a lower speed than said firstcoaxial drive outlet from a planet carrier of said gearbox.
 2. The mixeraccording to claim 1, wherein said transmission means includes transfermeans configured to convey, from said epicyclic gearbox to saiddownwardly-facing drive outlet, rotational drive at a substantiallylower speed than said first and second coaxial drive outlets.
 3. Themixer according to claim 1, wherein, in use of the stand mixer, one orboth of the first and second driving outlets and the downwardly-facingdrive outlet operate simultaneously.
 4. The mixer according to claim 1,wherein the downwardly-facing drive outlet and the coaxial drive outletsare driven by the same motor and epicyclic gearbox arrangement.
 5. Thestand mixer according to claim 1, in which the motor is housed in thesupport means.
 6. The stand mixer according to claim 1, wherein thedownwardly-facing drive outlet is a planetary drive outlet.
 7. The mixeraccording to claim 1, further comprising means associated with saidcoaxial outlets for encouraging fluid spilt in the vicinity of saidcoaxial outlets to flow into a collection means, and further meansadapted to conduct collected fluid out of the mixer; thereby impedingingress of said fluid into said gearbox.
 8. A kit comprising: a standmixer according to claim 1, a first attachment for coupling to a firstdrive outlet of the stand mixer; a second attachment for coupling to asecond drive outlet of the stand mixer; and a tool for coupling to adownwardly-facing drive outlet of the stand mixer.
 9. The kit accordingto claim 1, wherein the first attachment comprises a blender attachmentconfigured to be attached to the first driving outlet running at ahigher speed such that blades of the blender attachment are drivendirectly by the first driving outlet.
 10. The kit according to claim 1,wherein the second attachment comprises a food processor having aprocessing tool, the processor being configured to be attached to thesecond driving outlet running at a lower speed such that the processingtool is driven directly by the second driving outlet.
 11. The kitaccording to claim 10, in which the food processor is a juicer.
 12. Thekit according to claim 1, wherein the first and second attachments eachcomprise a drive coupling configured to transfer rotational drive formthe first and second drive outlets through the base of the attachment torotatable food processing tools mounted within the attachment.
 13. Thekit according to claim 1, wherein the first and second attachments areeach fitted with a closable lid having a safety interlock arranged toprevent the tools being driven unless the lid is closed.
 14. The kitaccording to claim 8, wherein the tool is a mixing tool.